Clearing device in calculating



2 Sheets-Sheet 1 L G ah k @w May' 22, 1951 E, K. amp

CLEARING DEVICEII EALCULATING MACHINES Filed Oct. 20, 1950 May 22, 1951 E. K. GRIP CLEARING DEVICE IN CALCULATING MACHINES 2 Sheets-Sheet 2 Filed Oct. 20, 1950 Patented May 22, :1951

CLEARING DEVICE IN CALCULATING MACHINES Erik K. Grip, Atvidabergsweden, assignor to Aktiebolaget Atvidaberg-Facit, Atvidaberg, Sweden, "a joint-stock company ofSweden Application October 20, 1950, Serial No. 191,110

. In Sweden November 4, 1949 6 Claims.

The present invention relates to electrically driven calculating machines of the pin-wheel or Odhner type, and more particularly to a clearing or zeroizing device for the product and quotient registers (the accumulator and the revolutions counter) in which the numeral wheels are mounted on a common shaft and the clearing is effected by rotating the numeral wheel shaft one revolution. For example, the machine may be of the type disclosed in the U. S. Patent No. 2,108,596.

The clearing mechanism according to the invention is an elegant, reliable and very small and compact device for effecting a key-operated clearing by means of the electric motor in machines of this type. The device according to the invention is substantially characterized in that a clearing key, when .depressedreleases a lever which'thereby is swung by a spring so as to rest, directly or through the intermediary of a roller, against a cam driven by the electric motor of the machine, whereafter the lever is forced back to its initial position bylthe motor-driven cam and thus actuates a .zeroizing segment so that said segment performs, ina manner known per se, the clearing operation.

An embodiment of the inventionis shown in detail in the accompanying drawings.

Fig. 1 is aside view of the elements included in the clearing device.

Fig. 2 is a section on IineII- -II in Fig. 1.

Fig. 3 is a perspective .view of the elements of the clearing device in the position shown in full lines in Fig. 1.

By means of a gear transmission, not shown, a shaft Iis connected to the electric motor of the calculating machine and carries va cam 2 which is rigid with the shaft. When the electric motor is running,the shaft l and the cam 2 rotate in the direction indicated by the arrow A in Fig. l (clockwise in Fig. 1).

A lever 4 is fulcrumed on a pivot 3 fixed in the frame of the machine. Said lever 4 carries at one end a rotatably mounted roller 5, and may be swung on the pivot 3 to a position in which the roller 5 rests against the earn 2 and, at the rotation of said cam, rolls on the periphery of the cam, as shown'in dotted lines in Fig. l.

The other'end of the lever 4 carries a pivot 6 on which one end of alink 1 is swingably mount-. ed, and the other end of said link 1 is in like manner mounted on a pivot 8 which in its turn is rigidly connected with one end of a toothed segment 9. This segment is swingably mounted on a pivot 10 which is fixed in the frame of the machine.

The toothed segment fiis ina well-known manner provided with a starting tooth ll whichis swingable around a pivot .l 2 .fixed on the toothed segment. The starting tooth is held. pressed against a stop M by means .of a spring 13, said stop being rigidly connected, ve. g. riveted, .tolthe segment. The toothed segment flgcooperates in theusual manner with a toothed wheel 15 .fixed on the shaft 16 carrying all .the numeral wheels in the register to be cleared by'the device according to the invention.

The toothed wheel I5 .is'zin a well-known manner provided witha recess 1.5a permitting the segment 9 to move freely (thus without rotating the toothed wheel it). from the position shown in full lines to the position .shown .in dash-anddot lines in Fig. 1. .However, when the segment is returning to :the. position shown in full lines in Fig. 1, the starting tooth will .in well-known manner engage the teeth of the wheel .15, whereafter this wheel engages the other teeth of :the segment 9 and is rotated in the direction of the arrow B (clockwise in Fig. l).

The numeral wheel shaft 16 is rigidly connected with a pin 1? (Fig. 2) which in wel1-known manner cooperates with a stationary cam 18 so that upon rotation the shaft lfiis'somewhat displaced axially in the direction of the arrow 0 (see Fig. 2) whereby the zeroizing or clearing teeth (not shown) on this shaft in well-known manner engage the corresponding teeth on the numeral wheels so that the latter are rotated to their zero position (cleared).

The clearing device is operated by means of a key I9 which is rotatably mounted on a'stationary shaft 28 inthe machine frame. The key arm carries a shoulder 19a cooperating with a projection 411 on the lever 4 in such a manner that when the shoulder [9a has engaged the projection to, the lever :3 and the segment 9 connected therewith are prevented from turning (clockwise in Fig. 1) against the action of a tension spring 2i acting on the segment 9.

After depression, the key I9 is returned to its initial position by a tension spring 22. Furthermore, a projection 23 on the keyv arm cooperates with a locking hook 24 which is fulcrumed on a stationary shaft 25 and is actuated by a tension spring 26. This locking hook 24locks, in certain cases, the key 19 in the depressed position as indicated by the position shown indot-and-dash lines in Fig. 1. The locking hook. is returned to its initial position against the action .of the tensionspring 26 by means of. a pin 21 fixed on the cam 2. Furthermore, a downwardly-directed projection of the key 19 cooperates with a contact device 28 for starting the electric motor of the machine. One end of the two springs 22 and 26 are fixed to a pin 30 riveted to the end wall 29 of the machine frame.

The device operates substantially in the following manner:

When the key I9 is depressed, the projection l9a slides off from the projection 4a of the lever 4 carrying the roller 5, and the spring 21 now swings the segment 9 and the lever 4 in the clockwise direction until said swinging movement is stopped by the roller contacting the cam 2. The parts are now in the position indicated in the dash-and-dot lines in Fig. 1. The teeth of the segment 9 now pass freely through the depression l5a in the toothed wheel 15 without rotating the same.

Upon the depression of the key [9 also the contact device 28 is actuated so that the electric current is closed and the motor of the machine is started and begins to rotate the shaft 1 with the cam 2. The depressed key will at the same time be locked in the depressed position by the locking hook 24 (see the position shown in dotand-dash lines in Fig. l)

The periphery of the cam 2 is designed in such a manner that, at the rotation in the clockwise direction, it presses the roller 5 back to its initial position so that the lever 4 and thus also the segment 9 are brought back to their initial positions (shown in full lines in Fig. l) When the segment 9 returns (anticlockwise in Fig. 1), the starting tooth ll engages the toothed wheel l5 (see Fig. 2) and during the return movement the shaft IE will consequently be rotated a Whole revolution so that the register is cleared in wellknown manner.

When the cam 2 has completed a whole revolution, the pin 21 on the cam will return the looking hook 24 to its initial position, where'after the key l9, against the action of the spring 22, returns to its initial position in which the projection 4a is hooked up and retained by the projection [9a on the key so that the final position becomes identical with the initial position.

The pin 21 is located in such a manner on the cam 2 that the locking hook 24 is returned to its initial position only in such a position of the cam 2 that the lever 4 is in the position shown in full lines in Fig. 1, or is moving towards said position. By this it is achieved that a complete clearing operation is always obtained after a single trically operated calculating machine of the Odhner type, comprising, in combination, a common shaft for the numeral wheels of the register, a clearing segment operatively connected with said common shaft 'to rotate it for clearing said numeral wheels, a lever for actuating said segment, a clearing key, said lever being normally locked but releasable at the depression of said key, a power-operated cam, and a spring for pressing said lever against said cam, when said lever has been released by said key.

2. A clearing device for the numeral wheels of a register in an electrically operated calculating machine of the Odhner type, comprising, in combination, a clearing key, a lever normally locked by said key but releasable at the manual depression thereof, a power-operated cam, a spring acting on said lever for pressing it in the direction towards said cam, a clearing segment, a link interconnecting said lever and said segment, a common shaft for the numeral wheels of said register, and a toothed wheel on said common shaft for cooperation with said toothed segment to be rotated thereby.

3. A clearing device for a register in an electrically operated calculating machine of the Odhner type, comprising, in combination, a common shaft for the numeral wheels of the register, a clearing segment operatively connected with said common shaft to rotate it for clearing said numeral wheels, a lever for actuating said segment, a clearing key, said lever being normally locked but releasable at the depression of said key, a spring-actuated hook for locking said key in its depressed position, a power-operated cam, and a spring for pressing said lever against said cam, when said lever has been released by said key.

i. A clearing device for a register in an electrically operated calculating machine of the Odhner type, comprising, in combination, a common shaft for the numeral Wheels of the register, a clearing segment operatively connected with said common shaft to rotate it for clearing said numeral Wheels, a lever for actuating said segment, a clearing key, said lever being normally locked but releasable at the depression of said key, a spring-actuated hook for locking said key in its depressed position, a power operated cam, a pin on said cam for restoring said locking hook to release said key, and a spring for pressing said lever against said cam, when said lever has been released by said key.

5. A clearing device for the numeral Wheels of a register in an electrically operated calculating machine of the Odhner type, comprising, in combination, a clearing key, electrical contacts for the electric current to the calculating machine, said contacts being controlled by said key, a lever normally locked by said key but releasable at the manual depression thereof, a power-operated cam, a spring acting on said lever for pressing it in the direction towards said cam. a clearing segment, a link interconnecting said lever and said segment, a common shaft for the numeral Wheels of said register, and a toothed wheel on said common shaft for cooperation with said tocthed segment to be rotated thereby.

6. A clearing device for the numeral Wheels of a register in an electrically operated calculating machine of the Odhner type, comprising, in combination, a clearing key, a hook on said key, a lever, a projection on said lever normally engaged by said hook to lock said lever, a power-operated cam, a spring acting on said lever for pressing it in the direction towards said cam, and also for pressing the projection on said lever against the hook on said key, a clearing segment, a link interconnecting said lever and said segment, a common shaft for the numeral Wheels of said register, and a toothed wheel on said common shaft for cooperation with said toothed segment to be rotated thereby.

ERIK K. GRIP.

No references cited. 

